Predictive role of P-wave axis abnormalities in secondary cardiovascular prevention

Recovery from Severe COVID-19 Is an Independent Predictor of Electrocardiographic Abnormal P-Wave Axis

AIM

Abnormal P-wave axis (aPwa) have been correlated with an increased risk of supraventricular arrhythmias. The aim of this study was to analyze whether infection with COVID-19 may cause a predisposition for supraventricular arrhythmia in the long term, following recovery.

MATERIALS AND METHODS

In this study, a total of 252 subjects with a confirmed history of COVID-19 (recovered COVID-19) and 251 healthy subjects without a history of COVID-19 were included. The recovered COVID-19 group was divided into three subgroups designated as mild, moderate, and severe according to the severity score of their chest CT. The aPwa data were obtained using 12-lead electrocardiography (ECG) and compared between the healthy subjects and the recovered COVID-19 subgroups.

RESULTS

This study showed that in the recovered severe COVID-19 subgroup the prevalence of aPwa was significantly increased compared to the controls and the other COVID-19 subgroups. No correlation could be detected in Spearman's Rho correlation between the existence of aPwa and the number of positive PCR tests for COVID-19 and the time elapsed after infection with COVID-19. The binary logistic regression analysis showed that recovery from severe COVID-19, the severity score of the chest CT in the recovered from COVID-19 subjects, and the existence of hypertension (HT) were all independent predictors of aPwa (hazard ratio: 3.542, 95% confidence interval: 1.398-8.969, p: 0.01; hazard ratio: 0.896, 95% confidence interval: 0.840-0.955, p < 0.001; hazard ratio: 2.710, 95% confidence interval: 1.079-6.804, p: 0.03, respectively).

CONCLUSIONS

Individuals who have recovered from severe COVID-19 have shown an increased prevalence of aPwa. The existence of aPwa was not associated with the number of positive PCR tests for COVID-19 or the time elapsed after infection with COVID-19. Therefore, recovery from severe COVID-19 is an independent predictor of electrocardiographic abnormal P-wave axis.

Ectopic atrial rhythm after superior septal approach to the mitral valve - an often under-reported entity

Purpose

Very few reports elaborate on the changes in P wave following superior septal approach to the mitral valve. We aimed to describe the changes in the P wave axis and other electrocardiographic changes following this approach among patients preoperatively in sinus rhythm.

Methods

We did a retrospective review of medical records among all our patients undergoing superior septal approach for mitral valve surgery from September 2014 to September 2019. Electrocardiograms during hospital stay and until 6-month follow-up were analyzed. A deviation in P wave axis from the normal range of + 30 to + 60° was classified as ectopic atrial rhythm.

Results

In the study population of 47 patients (age 16-75 years, 51.3 ± 13.6 years; M:F ratio 3.7:1), who were in normal sinus rhythm preoperatively, 34 patients (72.3%) had a visible P wave on electrocardiogram (ECG) at discharge. Among them, the P wave axes of 17 patients (36.2%) were within normal range (normal sinus rhythm), whereas 17 patients (36.2%) had ectopic atrial rhythm at discharge. The most frequent abnormal P wave axis was between 0 and - 30° (12 patients). At 6 months, 8 patients (17.0%) had a persistent ectopic atrial rhythm. These patients underwent a Holter test at 6 months and were followed up for symptomatic bradycardia for 3 years. None of the patients with ectopic atrial rhythm required pacemaker insertion.

Conclusion

Persistence of ectopic atrial rhythm at 6 months is common (17%) after superior septal approach. Documentation of P wave axis after this approach will help avoid missing it. These patients may be kept on follow-up to look for symptomatic bradycardia.

Paediatric/young versus adult patients with long QT syndrome

Introduction

Long QT syndrome (LQTS) is a less prevalent cardiac ion channelopathy than Brugada syndrome in Asia. The present study compared the outcomes between paediatric/young and adult LQTS patients.

Methods

This was a population-based retrospective cohort study of consecutive patients diagnosed with LQTS attending public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF).

Results

A total of 142 LQTS (mean onset age=27±23 years old) were included. Arrhythmias other than VT/VF (HR 4.67, 95% CI (1.53 to 14.3), p=0.007), initial VT/VF (HR=3.25 (95% CI 1.29 to 8.16), p=0.012) and Schwartz score (HR=1.90 (95% CI 1.11 to 3.26), p=0.020) were predictive of the primary outcome for the overall cohort, while arrhythmias other than VT/VF (HR=5.41 (95% CI 1.36 to 21.4), p=0.016) and Schwartz score (HR=4.67 (95% CI 1.48 to 14.7), p=0.009) were predictive for the adult subgroup (>25 years old; n=58). A random survival forest model identified initial VT/VF, Schwartz score, initial QTc interval, family history of LQTS, initially asymptomatic and arrhythmias other than VT/VF as the most important variables for risk prediction.

Conclusion

Clinical and ECG presentation varies between the paediatric/young and adult LQTS population. Machine learning models achieved more accurate VT/VF prediction.

P-wave axis is associated with all-cause mortality in diabetes: The ACCORD trial

Abnormal P-wave axis (PWA) has emerged as a novel marker of risk for both cardiovascular disease (CVD) and all-cause mortality (ACM) in the general population, though this relationship has not been adequately explored among those with type 2 diabetes (DM2). We aimed to explore the association between abnormal PWA and ACM among a large, well-phenotyped group of participants with DM2 from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. This analysis included 8899 ACCORD participants with available PWA data on baseline electrocardiogram. Cox proportional hazards models were used to examine the association between PWA and ACM in models adjusted for demographics, ACCORD trial treatment assignment, and potential confounders. PWA was modeled as either normal (0° -75°) or abnormal (<0° or >75°). Over 44,000 person-years of follow up, there were 609 deaths. Participants with abnormal PWA had increased risk of ACM (HR 1.61, 95% CI 1.25-2.08). After multivariable adjustment, the association remained significant (HR 1.33, 95% CI 1.03-1.72). This relationship was similar in subgroups stratified by age, race, sex, and history of CVD. Among ACCORD trial participants, abnormal PWA was associated with an increased risk of mortality. Abnormal PWA may have added value beyond traditional risk factors in prediction models.

Prognostic significance of P-wave morphology in patients with coronary artery disease

INTRODUCTION

The prognostic significance of P-wave morphology in patients with coronary artery disease (CAD) is not well-known.

METHODS

A total of 1946 patients with angiographically verified CAD were included in the Innovation to reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study. The P-wave morphology could be analyzed in 1797 patients.

RESULTS

During 7.4 ± 2.0 years, a total of 168 (9.3%) patients died or experienced resuscitation from sudden cardiac arrest (SCA), 43 (2.4%) patients experienced sudden cardiac death (SCD) or were resuscitated from SCA, 37 (2.1%) patients succumbed to non-SCD (NSCD), and 88 (4.9%) patients to noncardiac death (NCD). Of the P-wave parameters, the absolute P-wave residuum (PWR), the heterogeneity of the P-wave morphology (PWH), and the P-wave duration (Pdur) had the closest univariate association with the risk of SCD/SCA (0.0038 ± 0.0026 vs 0.0022 ± 0.0017, P < .001; 11.0 ± 5.2 vs 8.6 ± 3.6, P < .01; 142.7 ± 16.9 vs 134.8 ± 14.3 milliseconds, P < .01; SCD/SCA vs no SCD/SCA, respectively). After adjustments with factors that were associated with the risk of SCD/SCA, such as diabetes, smoking, left bundle branch block, high-sensitivity C-reactive protein, and high-sensitivity troponin T, PWR (P < .001), PWH (P < .05), and Pdur (P < 0.01) still predicted SCD/SCA but not non-sudden cardiac death. When these parameters were added to the SCD/SCA clinical risk model, the discrimination and reclassification accuracy of the risk model increased significantly (P < .05, P < .001) and the C-index increased from 0.745 to 0.787.

CONCLUSION

The P-wave morphology parameters independently predict SCD/SCA in patients with CAD.

P-wave duration is a predictor for long-term mortality in post-CABG patients

Risk stratification in secondary prevention has emerged as an unmet clinical need in order to mitigate the Number-Needed-to-Treat and make expensive therapies both clinically relevant and cost-effective. P wave indices reflect atrial conduction, which is a sensitive marker for inflammatory, metabolic, and pressure overload myocardial cell remodeling; the three stimuli are traditional mechanisms for adverse clinical evolution. Accordingly, we sought to investigate the predictive role of P-wave indices to estimate residual risk in patients with chronic coronary artery disease (CAD). The cohort included 520 post-Coronary Artery Bypass Grafting patients with a median age of 60 years who were followed for a median period of 1025 days. The primary endpoint was long-term all-cause death. Cubic spline model demonstrated a linear association between P-wave duration and incidence rate of long-term all-cause death (p = 0.023). P-wave >110ms was a marker for an average of 425 days shorter survival as compared with P-wave under 80ms (Logrank p = 0.020). The Cox stepwise regression models retained P-wave duration as independent marker (HR:1.37; 95%CI:1.05–1.79,p = 0.023). In conclusion, the present study suggests that P-wave measurement may constitute a simple, inexpensive and accessible prognostic tool to be added in the bedside risk estimation in CAD patients.